(2015GIS)北斗静止轨道卫星信号盲区快速并行解算方法

北斗系统静止轨道卫星信号盲区解算方法复杂、串行计算耗费时间长,需在并行环境下利用更多的计算资源进行北斗盲区的快速解算。本文在分析北斗盲区解算原理与算法并行特征基础上,提出了基于动态盲区影响域的并行解算方法,并以栅格单元为并行粒度进行任务划分,实现了北斗盲区的高效并行解算。基于全国范围59景数字高程模型数据,利用8进程进行盲区并行解算,耗费时间约为5小时。实验测试结果表明：算法的并行效率随着进程数的增加有所衰减,但稳定在96%以上。基于本文方法实现的程序中间件已集成应用于高性能地理信息平台中,应用效果良好。     

并行规约与扫描原语在ReRAM架构上的性能优化

规约与扫描是并行计算中的核心原语,其并行加速至关重要。然而,冯·诺依曼体系结构下无法避免的数据移动使其面临“存储墙”等性能与功耗瓶颈。近来,基于ReRAM等非易失存储器的存算一体架构支持的原位计算可一步实现矩阵-向量乘,已在机器学习与图计算等应用中展现了巨大的潜力。提出面向忆阻器存算一体架构的规约与扫描的并行加速方法,重点阐述基于矩阵-向量乘运算的计算流程和在忆阻器架构上的映射方法,实现软硬件协同设计,降低功耗并提高性能。相比于GPU,所提规约与扫描原语可实现高达两个数量级的加速,平均加速比也可达到两个数量级。分段规约与扫描最大可达到五个(平均四个)数量级的加速,并将功耗降低79%。     

并联波浪补偿系统的鲁棒控制方法

研究了基于绳牵引并联机构的新型波浪补偿系统的鲁棒控制方法。将环境作用力和不可测参数从动力学方程中分离出来,看作系统干扰,然后根据李亚普诺夫稳定性理论推导了控制律。针对绳索冗余的情况,提出了一种基于交互投影的绳索张力分布算法。当存在张力分布的可行解时,该算法能够得到远离张力限制边缘的"安全"最优解;当不存在可行解时,该算法能够得到满足张力限制条件的最佳近似解。为了提高鲁棒控制的实用性,还研究了负载惯性参数辨识方法。仿真结果表明,以上理论与方法对于波浪补偿系统是非常有效的。     

联合作战中作战单元决策演化博弈研究

利用演化博弈理论,探讨了联合作战中担负相同作战任务的作战单元间其策略选择根据利益变化的演化过程,建立了复制动态方程并求得平衡点解,通过复制动态的相位图直观反映了博弈的演化稳定策略,并通过Malab软件对作战单元策略选择与收益关系进行了仿真,其行为选择的演化结果与相位图展示具有一致性。研究结论表明,收益大小及变化是作战单元策略改变的重要依据,最后针对提高作战单元间的策略稳定性提出对策建议.     

Insurgency in Afghanistan: implications for Pakistan's internal and external security

In the aftermath of 9/11, the USA embarked on a massive global hunt for terrorists and launched its “Operation Enduring Freedom” in Afghanistan. Its failure to control insurgency in Afghanistan spilled over into Pakistan, with disastrous consequences. The resurgence of the Taliban with more formidable tactics and maneuvering skills has become more troublesome for both Afghanistan and Pakistan and for the USA and its allied forces. The fierce comeback of the insurgents has challenged the political and territorial integrity of Pakistan, one that it cannot tolerate. This article analyzes the current situation and its implications for Pakistan's security. Moreover, it looks into the internal and external security complexities that Pakistan faces and the possible implications of the US exit strategy for Pakistan's security. It concludes that the security situation in Pakistan is continuously deteriorating and no part of her territory is immune from terrorists' attacks. To be successful, Pakistan must pursue a broad-based strategy that encompasses military, political, social, economic and informational domains aimed at accomplishing four major objectives: (1) elimination of foreign terrorists and their facilitators; (2) strengthening of the political and administrative institutions in the Federally Administered Tribal Areas (FATA); (3) establishing a safe and secure environment conducive for sustained development and the realization of real socio-economic progress and (4) integrating the FATA into the national mainstream. In the long term, a strategy based on the concept of “Enlightened Moderation” is the right solution, not only to the internal problems of Pakistan but also for the Muslim world and the international community.     

建立装备成体系建设模式，为加快海洋强国建设提供强大力量支撑

建设海洋强国战略目标、建设强大海上军事力量需要探索中国特色的装备体系建设新模式。针对未来信息化战争体系对抗的特点,在研究中外武器装备体系建设经验基础上,提出了海上军事力量装备成体系建设的新模式,并讨论了海上军事力量装备成体系建设的有关问题。     

可变速率调制器研究及其FPGA实现

提出了一种变速率调制系统的设计方法。基于现场可编程门阵列(FPGA),在硬件系统中实现了新方法。所设计的系统能够处理(13.5~300)Mbps连续变化的比特速率。通过将整个可变速率范围分成若干小段,分别经过不同倍数的采样滤波,保证了所有符号速率对应的数据能够被调制到数模转换芯片(DAC)处理范围内。给出了系统整体设计结构,分析了硬件实现时的难点,论述了并行采样滤波与并行载波生成等设计方法。硬件实现结果表明,所提出的设计方法能够实现对较宽范围内连续可变速率信号的调制。系统的易扩展性也保证了所设计结构能够处理更宽的变速率范围。     

Enmeshed in insurgency: Britain's protracted retreats from Iraq and Afghanistan

Ten years of counterinsurgency in Iraq and Afghanistan have produced little in Britain's national interest. This article examines the political objectives set in these wars and the reasons why they have proved elusive. The core foreign policy aim was to sustain Britain's position as a great power by assuming responsibility for global order. Alliances with the United States and NATO would be the diplomatic tool for pursuing this aim. These alliances brought obligations, in the shape of agreed common threats. Rogue regimes with weapons of mass destruction and international terrorists harboured in failed states were deemed the primary threats to British security. Military means were therefore used in Iraq and Afghanistan to attack them. Whether Tony Blair's vision of global order ever made sense is debatable, and it attracted scepticism from the outset. The article argues experience in Iraq and Afghanistan showed that a strategy to eliminate terrorism (the WMD threat turned out never to have existed) by expeditionary counterinsurgency could only fail. Therefore the attention lavished on operational-level performance by most studies is misplaced, because no amount of warfighting excellence could make up for strategic incoherence. Finally, the article proposes the more important question arising from the last ten years is why the UK pursued a futile strategy for so long. The difficulties associated with interpreting events, a malfunctioning strategic apparatus, weak political oversight, and bureaucratic self-interest are posited as the most significant explanations.     

Colombia: Changing strategy amidst the struggle

From 1965 to the present, Colombia has been confronted by the insurgency of the Revolutionary Armed Forces of Colombia (FARC). The threat reached a new level in 1996 with the advent of mobile warfare, whereby large units sought to neutralize the military in an effort to seize power and institute a Marxist-Leninist regime. Unlike Vietnam, what followed was a regaining of the strategic initiative by the government and a decimation of the insurgent threat. This was accomplished with US assistance but from first to last was driven by Colombian leadership and strategy. The strategy which led to this signal change, ‘Democratic Security’, unfolded under the leadership of President Álvaro Uribe. It was a civil–military partnership, which sought to expand the writ of Colombian democracy to all elements of society. Securing the population provided the shield behind which economic, social, and political life could occur as driven by the will of the people. It was the agreement upon legitimacy as the strategic goal and reform as the route to that goal which allowed the Colombians and the Americans to work so well together.     

A best practice for assessment in counterinsurgency

In September 2011, the Commander of the International Security Assistance Force (ISAF) in Afghanistan directed the Afghan Assessment Group to redesign the way in which ISAF was assessing the status of the war, and to be ‘revolutionary’ in so doing. The resulting assessment paradigm was novel, non-doctrinal, and effectively addressed the unique complexities of the counterinsurgency in Afghanistan and the needs of the ISAF Commander. It had a two-tier structure consisting of both strategic and campaign assessments. The former focused on answering a set of strategic questions in narrative, analytic form to address the strategic environment, while the latter used a set of standards and accompanying narrative responses to gauge accomplishment of campaign tasks. Both tiers captured the current state of the war while maintaining an eye on future challenges and opportunities. The two assessments and their associated processes were designed to stimulate discussions leading directly to decisions by senior leaders on actions they could take, direct, or request. While any assessment paradigm will have advantages and disadvantages, an examination of the pros and cons of this assessment paradigm makes clear that it should be considered a ‘best practice’ in the field of counterinsurgency assessment.